Rotatable cam-piece for the control of needle butts in a circular knitting machine



Aprll 24, 1962 H.-LUI AK 3,030,785

ROTATABLE CAM-PIECE FOR THE CONTROL OF NEEDLE BUTTS IN A CIRCULAR KNITTING MACHINE Filed Sept. 11, 1959 United States Patent Office 3,fi30,785 Patented Apr. 24, 1962 3,030,785 ROTATABLE CAM-PIECE FOR THE CONTROL OF NEEDLE BUTTS IN A CIRCULAR KNITTING MACHINE Hynek Luhak, Trebic, Czechoslovakia, assignor to Sdruzeni podniku textilniho Strojirenstni, Chrastava, Czechoslovakia Filed Sept. 11, 1959, Ser. No. 839,385 Claims priority, application Czechoslovakia Sept. 13, 1958 9 Claims. (Cl. 66--5tl) The present invention relates to a rotatable cam-piece for the control of needle butts in a circular knitting machine in particular in a one-cylinder circular knitting machine for the production of stockings.

During certain operational steps of the machine the cam-piece may assume a position in which its cam face extends in a radial plane with respect to the cylinder axis without causing the path of the needle butts to change or it may assume a position in which the cam face is inclined relative to the radial plane and in which the needles are lifted by the cam for the purpose of knocking on the loops.

It is known to control rotatable cam pieces by means of a lever system. The pressure of the needle butts hitting the cam piece adversely affects such a lever system.

The described disadvantage is substantially overcome by the present invention according to which the stem of a cam piece is connected With a Bowden-cable by means of a cross-bar which is guided in an oblique slot of an immobile casing. The stem has a straight longitudinal bore in which one end of the Bowden-cable is fastened to the crossbar which passes through straight longitudinal slots in the stern.

Details of the device according to the invention will be seen from the following description of one embodiment of the invention and from the accompanying drawings, in which FIG. 1 shows a circular knitting machine equipped with the cam arrangement of the invention in fragmentary elevational section substantially through the axis of the needle cylinder;

FIG. 2 shows the cam piece of the apparatus of FIG. 1 with the stem and inserted Bowden cable in a perspective view;

FIG. 3 is a corresponding perspective view of the support carrying the cam piece;

FIG. 4 shows a detail of the device of FIG. 3;

FIG. 5 is a perspective view of a sleeve of the apparatus of FIG. 1;

FIG. 6 is a perspective view of a locking wire cooperating with the sleeve of FIG. 5.

Referring now to the drawing in detail, and initially to FIG. 1 which shows some elements of a conventional circular knitting machine equipped with the cam arrangement of the invention, there is seen a needle cylinder 17 of which only a peripheral portion is shown in section along the axis of the cylinder. A plurality of needles 18 of which only one is visible are axially slidable in peripheral grooves 19 of the cylinder. The butts 20 of the needles extend radially from the groove for cooperation with cams arranged on a fixed portion 21 of the machine frame. The structure described so far is well known.

The cam piece 1 which has an elongated stem 2 formed with a longitudinal slot 3 and a longitudinal straight bore 4 is mounted for rotation in a tube 5 on a bracket 6. The bracket is secured to the fixed frame portion 21. An end face of the bracket 6 adjacent the cam piece 1 is curved about an axis perpendicular to the axis of rotation of the stem 2, as best seen from FIG. 3. The position of the tube 5, which has an end portion of reduced diameter inserted in an opening of the bracket 6, is secured by a set screw 7. The free part of the tube 5 is provided at two opposite sides with parallel oblique slots 8 having each a straight terminal length (FIG. 4) which forms an angle of inclination a with the longitudinal axis of the tube. by a short straight section y connected with the inclined portion by a curved slot portion having a radius of curvature r. The straight section extends parallel to the longitudinal axis of the stem 2, in order to ensure a positive connection of the tube 5 with a cross-bar 11 when the pressure of the needle butts 20 tends to tilt the cam piece 1 and also to ensure the exact operative position of the latter. A Bowden cable 9 is guided in the longitudinal bore 4 of the stem 2, and its end-piece 10 is fastened to the cross-bar 11 by a pin or a screw. The cross-bar 11 passes through the straight longitudinal slot 3 in the stem 2 and also through the oblique slots 8 in the tube 5.

The cross-bar 11 is secured in the stem 2 by a sleeve 12 which is fitted slidably over the tube 5 and has a peripheral groove 13 for the insertion of a locking Wire 14 which engages corresponding grooves in the ends of the cross bar 11 to hold the bar in place. A spring 15 is located in the longitudinal bore 4. One end thereof abuts against the cross-bar 11 and its other end against an adjustable closure 16. The spring 15 urges the cross-bar 11 with the sleeve 12 to move in the direction towards the cam-piece 1. The closure 16 threadedly engages the bore 4 at the end of the stem 2 and is secured by means of a nut 17 against loosening.

The arrangement described operates as follows:

Tension exerted by the Bowden-cable 9 in a direction away from the cam-piece -1 causes the cross-bar 11 to be displaced in the straight longitudinal slot 3 of the stem 2, while following at the same time the oblique slot 8 in the fixed tube 5, thus causing rotational movement of the cam piece 1. At the end of the rotational movement the cross-bar 11 reaches the short straight section of the slot 8 which extends parallel to the longitudinal axis of the stem 2. Any pressure produced by the needle butts hitting the inclined face of the cam-piece 1 is now absorbed by the wall of the slot 3 and is not transmitted to the Bowden-cable 9.

The control arrangement for a rotary cam-piece according to the present invention is not limited to circular knitting machines, but can be used also in connection with flat knitting machines.

I claim:

1. A cam arrangement for actuating movement of needle butt means in a knitting machine, comprising a support; a first member fixedly fastened on said support and having an axis; a second member mounted on said first member for rotation about said axis, one of said members being formed with an axially extending elongated recess, and the other member being formed with an elongated recess axially extending at an angle relative to i the recess of said one member; bar means secured to said first member for axial movement relative thereto, said bar means simultaneously engaging said recesses and radially extending therein for actuating rotation of said second member relative to said first member during said axial movement of said bar means; a cam member mounted on said second member and having an axially extending cam face; and means for actuating said axial movement of said bar means.

2. A cam arrangement for actuating movement of needle butt means in a knitting machine, comprising a support; a tubular bearing member fixedly mounted on said support and having an axis; a tubular stem member rotatable in said bearing member about said axis, one of said members being formed with an elongated slot ex- The other end of the slot 8 is formedv tending in an axial direction, the other one of said members being formed with an elongated slot extending in an axial direction at an angle to the elongated slot of said one member, respective portions of said slots being adapted to be radially aligned by rotation of said stem member in said bearing member; a bar member axially movable on said bearing member and radially extending simultaneously into aligned portions of said slots for actuating relative rotation of said bearing member and of said stem member during axial movement of said bar member; a cam member mounted on said stem member and having an axially extending cam face; and actuating means for actuating said axial movement of said bar member.

3. A cam arrangement as set forth in claim 2, wherein one of said slots extends in a direction substantially parallel to said axis, and the other slot is obliquely i11- clined relative to said one slot.

4. A cam arrangement as set forth in claim 2, wherein one of said slots extends in a direction substantially parallel to said axis, and the other slot has a portion obliquely inclined relative to said slot and a terminal portion communicating with said inclined portion and extending in substantially said parallel direction.

5. A cam arrangement as set forth in claim 2, wherein said actuating means include a resilient member permanently urging said bar member tomove axially in one direction, and a tension member for moving said bar member in a direction opposite to said one direction against the restraint of said resilient member.

6. A cam arrangement as set forth in claim 5, wherein said tension member is a Bowden-cable.

1. A cam arrangement as set forth in claim 2, wherein said bar member is elongated and longitudinally extends in a substantially radial direction relative to said axis, said arrangement further comprising securing means for securing said bar member in a fixed radial position.

8. A cam arrangement as set forth in claim 7, said securing means including a sleeve member slidable on said bearing member and secured to said bar member.

9. A cam arrangement for actuating movement of needle butt means in a knitting machine, comprising a support; a plurality of elongated needles longitudinally movable on said support and juxtaposed in a row extending transversely of the direction of elongation of said needles, said needles being jointly movable on said support in the direction of extension of said row, said direction of elongation and said direction of extension jointly defining a surface of movement; a tubular bearing member fixedly mounted on said support and having an axis transverse of said surface; a tubular stern member rotatable in said bearing member about said axis, one of said members being formed with an elongated slot extending in an axial direction, the other one of said members being formed with an elongated slot extending in an axial direction at an angle to the elongated slot of said one member, respective sequential portions of said slots being adapted to be radially aligned sequentially by rotation of said stern member in said bearing member; a bar member axially movable on said bearing member and radially extending simultaneously into aligned portions of said slots for actuating relative rotation of said bearing member and of said stem member during axial movement of said bar member; a cam member mounted on said stem member and having an axially extending cam face for engagement with said needles for actuating longitudinal movement thereof when said cam face is in a position inclined relative to said direction of joint movement of said needles during said joint movement; and actuating means for actuating said axial movement of said bar member.

Nye Dec. 3, 1889 Wiesinger May 1, 1956 

